In a photolithography process of a semiconductor device fabrication process, a fine resist pattern is formed by performing processes such as a hydrophobic conversion process for the surface of a semiconductor wafer (hereinafter “a substrate” or “wafer”) first, and then, a coating and heating process of BARC (Bottom Anti-Reflective Coating), an exposing process, and then an developing process of a solubilization portion and removing the same.
Prior to the exposing process of the resist pattern, a series of processes are continuously performed including a coating process of BARC, a heating process (a pre-baking) to evaporate the solvent inside the applied BARC, a cooling process, a resist coating process that applies a resist to a cooled wafer, and a heating process (a pre-baking) to evaporate the solvent inside the applied resist solution. Also, after the exposing process of the resist pattern, a series of processes are performed including a heating process (a pre-baking after the exposure process), a cooling process, and an exposure process that applies an exposure solution to a cooled wafer to expose the wafer.
Recently, the foot prints of the entire coating/developing apparatus that performs a coating and developing processes of a semiconductor wafer has been increased as the wafer size becomes larger (e.g. 450 mm).
Moreover, the processing capability of wafers per unit time may be increased for a cost saving, and for this reason, multiple processing units are included in a coating/developing apparatus thereby further increasing the foot prints of the entire apparatus.
Japanese Laid-Open 2003-7795 shows an exemplary coating/developing apparatus where each processing unit is placed on both sides from the cassette side toward the exposure apparatus, and a common wafer transfer arm is provided at the center.